Ohio river placed on US EPA priority list September 23, 2009 @ 05:39 PM The Associated Press Herald-Dispatch.com MARION, Ohio The Little Scioto River in central Ohio has been designated by the U.S. Environmental Protection Agency as one of the nations most complex hazardous waste sites, making it eligible for federal investigation and cleanup. The agency announced Wednesday that the river near Marion is one of 11 new sites on the Superfund National Priorities List of areas that pose a risk to people and the environment. The EPA says four miles of river sediment are contaminated with toxin-containing coal tar creosote from the former Baker Wood Preserving Co. The lumber preservation company operated a treatment plant in Marion until the 1960s. The government excavated 68,000 tons of sediment and shoreline from 2002 to 2006. The Little Scioto flows into the Scioto River at Portsmouth, a main tributary of the Ohio River.